#第一题
num_str='0123456789'
print(num_str[2:6])
print(num_str[2::])
print(num_str[::-5])
print(num_str[::])
print(num_str[::2])
print(num_str[2::])
print(num_str[-1:-3])
print(num_str[::-1])
#使用zip组合下面两个元组，变为列表嵌套元组格式

a=(1,2,3)
b=('a','b','c')
print(list(zip(a,b)))

#使用enumerate把seasons=['spring','summer','fall','winter']
seasons=['spring','summer','fall','winter']
my_list=print({value:index for index,value in enumerate(seasons)})
seasons=['spring','summer','fall','winter']
print({value:index for index,value in enumerate(seasons)})
u=(1,2,3,4)
v=('a','b','c','d')
print({v:u for u,v in zip(u,v) })